Second near-infrared upconversion and downconversion luminescence in a core–multishell nanophotoswitch. (4th July 2022)

• Record Type: Journal Article
• Authors: Lin, Hao; Cheng, Zhiyuan; Xu, Dekang; Zheng, Xuegang; Liu, Tong; Xu, Liqin; Ma, Ying; Zhang, Yueli
• Is Part Of: New journal of chemistry. Volume 46:Number 28(2022)
• Page Start: 13766
• Page End: 13773
• Publication Date: 2022-07-04
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d2nj01793h
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Ho 3+ is selected as both the energy trapping center and NIR-II emitter in the core. Abstract : The development of a NIR-II (near-infrared-II: 1000–1700 nm) nanophotoswitch is urgently needed, due to its deeper tissue penetration and higher resolution imaging. In this work, a new type of NIR-II upconversion (UC) and downconversion (DC) nanophotoswitch (NaErF4 :Ho@NaYF4 @NaYbF4 :Tm@NaYF4 core–multishell nanoparticles) is presented. When the switch is open, ultraviolet (UV)–blue emissions and intense red UC (Er 3+ :654 nm) and NIR-II DC (Er 3+ :1520 nm) emissions are simultaneously obtained under 980 nm NIR-I (near-infrared-I: 700–1000 nm) excitation, which shows potential application for real-time visible- and NIR-II-imaging in the photodynamic therapy (PDT) process. When the switch is closed, UV–blue emissions disappear while red UC (Er 3+ :654 nm) and NIR-II UC (Ho 3+ :1154 nm) emissions remain under 1532 nm NIR-II excitation, which may be used for real-time visible- and NIR-II-imaging before conducting PDT. This novel NIR-II nanophotoswitch displays special advantages in the biomedical field.